in 4e though, those arms are only mechanized two ways
their racial power, which every race gets one of
and something about being able to carry a slightly heavier load of stuff for encumbrance
they also get feats they could take represented by those arms, but again, so does every race get racial feats
one of the things I love about 4e is that having something ridiculous like 4 arms does not make you overpowered